It is known to construct surface treatment devices such as rotary car wash brushes and depending friction curtains using strips of pliable material such as non-woven needle punched felt and/or pliable foam plastic. To construct such a combination, the strips may be folded around a length of a rigid plastic rod and stapled or stitched together to form an edge bead. This edge bead can then be inserted end-wise into a slot in a hub or other carrier structure, the slot having a circular cross section and a narrow opening which permits the material of the element to extend outwardly or downwardly therefrom. An example of this structure in a friction curtain apparatus is illustrated in U.S. Pat. No. 4,096,600 issued Jun. 27, 1978 to James A. Belanger of Northville, Mich. A similar structure wherein the carrier is arcuate and used to form a brush hub is illustrated in the U.S. Pat. No. 4,005,028 issued Oct. 25, 1977 to James A. Belanger of Northville, Mich. As is more fully explained in the '028 patent, the surface treatment element may be abrasive for working or burnishing, or may comprise soft, non abrasive materials for washing, drying, buffing or polishing automobiles and other articles.